For sale is this vintage IWC piece with solid 18k gold case and a caliber 401 ultrathin manual wind movement. The history behind these cases is that during this era import duties were very high on precious metal watches in Japan. So IWC contracted with their distributor in the country, Isomura, to manufacture the case and shipped the incomplete watches to Japan for final assembly. These watches are denoted with a small Japanese flag on the inside of the caseback, and are very rare. The case measures 34.5mm wide, with a 41.45mm lug to lug, and is just 8.65mm thick. Lugs are 18mm, and it is on a vintage NOS lizard calf strap. The case is in exceptional condition for its age, with sharp edges and thick, unpolished lugs. The dial is likewise very good, with light patina and original lettering. Given the large dial and low profile it wears a bit large for the measurements. Shot of the watch on my 6.7" wrist provided for reference on the sizing. Serial number dates this to the late 1950s. The watch winds and sets normally, and in timing on my desk only gained a handful of seconds over a day. Imgur album: [https://imgur.com/a/Bf4MTEj](https://imgur.com/a/Bf4MTEj) Timestamp: [https://imgur.com/v36G9zS](https://imgur.com/v36G9zS) Asking **$1095 shipped** in the US, via wire, Zelle, or Venmo. I will ship internationally and only charge the difference in cost on top. Please let me know if you have any questions!